填写缺少的日期并添加“0”
填写缺少的日期并添加“0”
提问于 2019-03-29 06:09:20
下面的代码按滑雪季(12月至3月)每年的月份生成SLC中的雪崩数量。由于此代码获取每年-月份的总数，因此它不会将雪崩次数为0的年份-月份计算在内。我如何填写我的表格，这样它将提供全年-月份？
# write the webscraper
library(XML)
library(RCurl)
library(dplyr)
avalanche<-data.frame()
avalanche.url<-"https://utahavalanchecenter.org/observations?page="
all.pages<-0:202
for(page in all.pages){
this.url<-paste(avalanche.url, page, sep="")
this.webpage<-htmlParse(getURL(this.url))
thispage.avalanche<-readHTMLTable(this.webpage, which=1, header=T,stringsAsFactors=F)
names(thispage.avalanche)<-c('Date','Region','Location','Observer')
avalanche<-rbind(avalanche,thispage.avalanche)
}
# subset the data to the Salt Lake Region
avalancheslc<-subset(avalanche, Region=="Salt Lake")
str(avalancheslc)
# convert the dates and get the total the number of avalanches
avalancheslc <- avalancheslc %>%
group_by(Date = format(as.yearmon(Date, "%m/%d/%Y"), "%Y-%m")) %>%
summarise(AvalancheTotal = n())
# pipe to only include Dec-Mar of each year
avalancheslc <- avalancheslc %>% filter(as.integer(substr(Date, 6, 7)) %in% c(12, 1:3))# the data right now looks like this
Date AvalancheTotal
1980-01 1
1981-02 1
.
.
.
# the data needs to look like this
Date AvalancheTotal
1980-01 1
1980-02 0
1980-03 0
1980-12 0
1981-01 0
1981-02 1
1981-03 1回答 1
Stack Overflow用户
发布于 2019-03-29 07:05:00
library("tidyverse")
library("lubridate")
# You data here...
# Simpler version
avalancheslc %>%
separate(Date, c("year", "month")) %>%
# Some years might be missing (no avalanches at all)
# We can fill in those with `full_seq` but
# `full_seq` works with numbers not characters
mutate(year = as.integer(year)) %>%
complete(year = full_seq(year, 1), month,
fill = list(AvalancheTotal = 0)) %>%
unite("Date", year, month, sep = "-")
# Alternative version (fills in all months, so needs filtering afterwards)
avalancheslc <- avalancheslc %>%
# In case `Date` needs parsing
mutate(Date = parse_date_time(Date, "%y-%m"))
# A full data frame of months
all_months <- avalancheslc %>%
expand(Date = seq(first(Date), last(Date), by = "month"))
# Join to `avalanches` and fill in with 0s
avalancheslc %>%
right_join(all_months) %>%
replace_na(list(AvalancheTotal = 0))页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/55407612
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